关闭应用时的Flutter agora视频通话屏幕

import 'package:flutter/material.dart';
import 'package:agora_rtc_engine/agora_rtc_engine.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> with WidgetsBindingObserver {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);
    if (state == AppLifecycleState.paused) {
      // 调用Agora SDK提供的方法，关闭视频通话界面
      AgoraRtcEngine.leaveChannel();
    }
  }

  @override
  Widget build(BuildContext context) {
    // 根据应用的生命周期状态，决定是否显示视频通话界面
    final isAppActive = WidgetsBinding.instance.lifecycleState == AppLifecycleState.resumed;
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Flutter agora视频通话屏幕'),
        ),
        body: isAppActive ? VideoCallScreen() : Container(),
      ),
    );
  }
}

class VideoCallScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // 在这里构建视频通话界面的UI
    return Container(
      child: Text('视频通话界面'),
    );
  }
}